TY  - JOUR
A1  - Yazdanbakhsh, Pedram
A1  - Solbach, Klaus
A1  - Bitz, Andreas
T1  - Variable power combiner for RF mode shimming in 7-T MR imaging
JF  - IEEE Transaction on Biomedical Engineering
N2  - This contribution discusses the utilization of RF power in an MRI system with RF mode shimming which enables the superposition of circularly polarized modes of a transmit RF coil array driven by a Butler matrix. Since the required power for the individual modes can vary widely, mode-shimming can result in a significant underutilization of the total available RF power. A variable power combiner (VPC) is proposed to improve the power utilization: it can be realized as a reconfiguration of the MRI transmit system by the inclusion of one additional matrix network which receives the power from all transmit amplifiers at its input ports and provides any desired (combined) power distribution at its output ports by controlling the phase and amplitude of the amplifiers’ input signals. The power distribution at the output ports of the VPC is then fed into the “mode” ports of the coil array Butler matrix in order to superimpose the spatial modes at the highest achievable power utilization. The VPC configuration is compared to the standard configuration of the transmit chain of our MRI system with 8 transmit channels and 16 coils. In realistic scenarios, improved power utilization was achieved from 17% to 60% and from 14% to 55% for an elliptical phantom and a region of interest in the abdomen, respectively, and an increase of the power utilization of 1 dB for a region of interest in the upper leg. In general, it is found that the VPC allows significant improvement in power utilization when the shimming solution demands only a few modes to be energized, while the technique can yield loss in power utilization in cases with many modes required at high power level.
Y1  - 2012
U6  - https://doi.org/10.1109/TBME.2012.2205926
SN  - 1558-2531
VL  - 59
IS  - 9
SP  - 2549
EP  - 2557
PB  - IEEE
CY  - New York
ER  - 
TY  - CHAP
A1  - Müller, Tim M.
A1  - Schmitt, Andreas
A1  - Leise, Philipp
A1  - Meck, Tobias
A1  - Altherr, Lena
A1  - Pelz, Peter F.
A1  - Pfetsch, Marc E.
T1  - Validation of an optimized resilient water supply system
T2  - Uncertainty in Mechanical Engineering
N2  - Component failures within water supply systems can lead to significant performance losses. One way to address these losses is the explicit anticipation of failures within the design process. We consider a water supply system for high-rise buildings, where pump failures are the most likely failure scenarios. We explicitly consider these failures within an early design stage which leads to a more resilient system, i.e., a system which is able to operate under a predefined number of arbitrary pump failures. We use a mathematical optimization approach to compute such a resilient design. This is based on a multi-stage model for topology optimization, which can be described by a system of nonlinear inequalities and integrality constraints. Such a model has to be both computationally tractable and to represent the real-world system accurately. We therefore validate the algorithmic solutions using experiments on a scaled test rig for high-rise buildings. The test rig allows for an arbitrary connection of pumps to reproduce scaled versions of booster station designs for high-rise buildings. We experimentally verify the applicability of the presented optimization model and that the proposed resilience properties are also fulfilled in real systems.
KW  - Optimization
KW  - Mixed-integer nonlinear programming
KW  - Water distribution system
KW  - Resilience
KW  - Validation
Y1  - 2021
SN  - 978-3-030-77255-0
SN  - 978-3-030-77256-7
U6  - https://doi.org/10.1007/978-3-030-77256-7_7
N1  - Proceedings of the 4th International Conference on Uncertainty in Mechanical Engineering (ICUME 2021), June 7–8, 2021
SP  - 70
EP  - 80
PB  - Springer
CY  - Cham
ER  - 
TY  - JOUR
A1  - Hagemann, Hans-Jürgen
A1  - Ihrig, H.
T1  - Valence change and phase stability of 3d-doped BaTiO3 annealed in oxygen and hydrogen. Hagemann, H. J.; Ihrig, H.
JF  - Physical Review B.. 20 (1979), H. 9
Y1  - 1979
SN  - 1095-3795
SP  - 3871
EP  - 3878
ER  - 
TY  - JOUR
A1  - Hüning, Felix
T1  - Using Trench PowerMOSFETs in Linear Mode
JF  - Power Electronics Europe (2012)
N2  - If we think about applications for modern Power MOSFETs using trench technology, running them in linear mode may not be top of the priority list. Yet there are multiple uses for Trench Power MOSFETs in linear mode. In fact, even turning the device on and off in switching applications is a form of linear operation. Also, these components can be run in linear mode to protect the device against voltage surges. This article will illustrate the factors that need to be considered for linear operation and show how Trench Power MOSFETs are suited to it.
Y1  - 2012
SN  - 1748-3530
SP  - 27
EP  - 29
PB  - DFA Media
CY  - Tonbridge
ER  - 
TY  - CHAP
A1  - Rausch, Lea
A1  - Friesen, John
A1  - Altherr, Lena
A1  - Pelz, Peter F.
ED  - Kliewer, Natalia
ED  - Ehmke, Jan Fabian
ED  - Borndörfer, Ralf
T1  - Using mixed-integer programming for the optimal design of water supply networks for slums
T2  - Operations Research Proceedings 2017
N2  - The UN sets the goal to ensure access to water and sanitation for all people by 2030. To address this goal, we present a multidisciplinary approach for designing water supply networks for slums in large cities by applying mathematical optimization. The problem is modeled as a mixed-integer linear problem (MILP) aiming to find a network describing the optimal supply infrastructure. To illustrate the approach, we apply it on a small slum cluster in Dhaka, Bangladesh.
Y1  - 2018
SN  - 978-3-319-89919-0 (Print)
SN  - 978-3-319-89920-6 (Online)
U6  - https://doi.org/10.1007/978-3-319-89920-6_68
N1  - International Conference of the German Operations Research Society (GOR), Freie Universiät Berlin, Germany, September 6-8, 2017.
SP  - 509
EP  - 516
PB  - Springer
CY  - Cham
ER  - 
TY  - JOUR
A1  - Ferrein, Alexander
A1  - Fritz, Christian
A1  - Lakemeyer, Gerhard
T1  - Using Golog for Deliberation and Team Coordination in Robotic Soccer / Ferrein, Alexander ; Fritz, Christian ; Lakemeyer, Gerhard
JF  - Künstliche Intelligenz : KI. 19 (2005), H. 1
Y1  - 2005
SN  - 0933-1875
SP  - 24
EP  - 30
ER  - 
TY  - CHAP
A1  - Fuchs, Britta
A1  - Ritz, Thomas
A1  - Strauch, Jakob
ED  - Obaidat, Mohammad S.
T1  - Usability of mobile applications : dissemination of usability engineering in small and medium enterprises
T2  - Proceedings of the International Conference on Data Communication Networking, e-Business and Optical Communication Systems : Rome, Italy, 24 - 27 July, 2012 ; [integrated in the ICETE (International Conference on e-Business and Telecommunications)]
Y1  - 2012
SN  - 978-989-8565-23-5
N1  - Nebentitel: DCNET; ICE-B; OPTICS
SP  - 272
EP  - 277
PB  - SciTePress
CY  - [Lissabon]
ER  - 
TY  - CHAP
A1  - Fuchs, Britta
A1  - Ritz, Thomas
T1  - Usability for Blended Shopping - Solving Major Flaws by Applying Usability Engineering and Proven Integration Technologies
T2  - Proceedings of the 11th International Conference on e-Business, ICE-B 2014, Vienna, Austria
Y1  - 2014
SN  - 978-989-758-043-7
U6  - https://doi.org/10.5220/0005113502160223
SP  - 216
EP  - 223
ER  - 
TY  - JOUR
A1  - Ritz, Thomas
A1  - Pisarczyk, Rafael
A1  - Sachtleben, Johanna
A1  - Leßenich, Nina
T1  - Usability Engineering maßgeschneidert : Modellbaukasten zur Entwicklung gebrauchstauglicher mobiler Software
JF  - Wissenschaft trifft Praxis
Y1  - 2014
SN  - 2198-8544 (Print)
SN  - 2198-9362 (Online)
N1  - Der Link führt zum vollständigen Heft, der Artikel beginnt auf S.79.
VL  - 1
IS  - 1
SP  - 79
EP  - 88
PB  - Begleitforschung Mittelstand-Digital c/o WIK-Consult GmbH
CY  - Bad Honnef
ER  - 
TY  - JOUR
A1  - Foltz, Christian
A1  - Schneider, Nicole
A1  - Wolf, Martin R.
A1  - Kausch, Bernhard
A1  - Schlick, Christopher
A1  - Luczak, Holger
ED  - Nagl, Manfred
T1  - Usability engineering
JF  - Collaborative and distributed chemical engineering : from understanding to substantial design process support; results of the IMPROVE Project. - (Lecture notes in computer science ; 4970)
Y1  - 2008
SN  - 978-3-540-70552-9
U6  - https://doi.org/10.1007/978-3-540-70552-9_21
SP  - 527
EP  - 554
PB  - Springer
CY  - Berlin
ER  - 
TY  - BOOK
A1  - Anthrakidis, Anette
A1  - Jahn, Roland
A1  - Ritz, Thomas
A1  - Schöttler, Mirjam
A1  - Wallenborn, Ramona
A1  - Warmke, Gisela
T1  - Urbanes eCarSharing in einer vernetzten Gesellschaft
Y1  - 2013
SN  - 978-3-943356-70-0
PB  - Steinbeis-Edition
CY  - Stuttgart
ET  - 1. Aufl.
ER  - 
TY  - BOOK
A1  - Ringbeck, Thorsten
T1  - Untersuchung opto-elektrischer Phasenregelkreise auf Basis von Photomischdetektoren hinsichtlich deren Anwendungspotential für die Photonik
Y1  - 2002
SN  - 3-8265-9789-3
N1  - Zugl.: Siegen, Univ., Diss., 2001.- (ZESS-Forschungsberichte ; Nr. 16)
PB  - Shaker-Verl.
CY  - Aachen
ER  - 
TY  - JOUR
A1  - Hillgärtner, Michael
A1  - Rinkleff, T
T1  - Untersuchung eines hybriden EMV-Simulationsverfahrens anhand eines virtuellen Komponententests
JF  - Technisches Messen. 70 (2003), H. 3
Y1  - 2003
SN  - 0340-837X
N1  - 2. ISSN: 0178-2312; 3. ISSN: 0171-8096
SP  - 133
EP  - 140
ER  - 
TY  - CHAP
A1  - Bensberg, Frank
A1  - Auth, Gunnar
A1  - Czarnecki, Christian
ED  - Hofmann, Georg Rainer
ED  - Alm, Wolfgang
T1  - Unterstützung von Wissenstransferprozessen durch Erschließung von Literaturdatenbanken - ein gestaltungsorientierter Ansatz auf Basis von Text Analytics
T2  - Wissenstransfer in der Wirtschaftsinformatik Fachgespräch im Rahmen der MKWI 2018
N2  - Angesichts des anhaltenden Wachstums wissenschaftlicher Veröffentlichungen werden Instrumente benötigt, um Literaturanalysen durch Digitalisierung produktiver zu gestalten. Dieser Beitrag stellt einen Ansatz vor, der bibliographische Daten aus der Literaturdatenbank EBSCO Discovery Service mithilfe von Text-Analytics-Methoden erschließt. Die Lösung basiert auf dem Textanalysesystem IBM Watson Explorer und eignet sich für explorative Literaturanalysen, um beispielsweise den Status quo emergierender Technologiefelder in der Literatur zu reflektieren. Die generierten Ergebnisse sind in den Kontext der zunehmenden Werkzeugunterstützung des Literaturrechercheprozesses einzuordnen und können für intra- sowie interinstitutionelle Wissenstransferprozesse in Forschungs- und Beratungskontexten genutzt werden.
KW  - Wissenstransfer
KW  - Text Analytics
KW  - Literaturdaten
KW  - Literaturanalyse
KW  - Literatur-analyse-prozess
Y1  - 2018
SN  - 9783981844207
N1  - MKWI 2018: Multikonferenz Wirtschaftsinformatik 2018 in Lüneburg, 06.03.2018-09.03.2018
SP  - 6
EP  - 15
PB  - IMI-Verlag ; Hochschule Aschaffenburg, Information Management Institut
CY  - Aschaffenburg
ER  - 
TY  - JOUR
A1  - Krause, Gregor
A1  - Kehle, Uwe
T1  - Unterstützung des Motorhochlaufs eines Pumpspeicherkraftwerks durch Mittel der Blindleistungskompensation / Uwe Kehle, Gregor Krause
JF  - Ertüchtigung von Kraftwerken und Netzen, insbesondere in den neuen Bundesländern. Energietechnische Gesellschaft <Deutschland> am 20. und 21. Oktober 1993 in Mannheim
Y1  - 1993
SN  - 3-8007-1967-3
N1  - ETG-Fachbericht ; 47
SP  - 287
EP  - 296
PB  - VDE-Verl.
CY  - Berlin [u.a.]
ER  - 
TY  - RPRT
A1  - Pisarczyk, Rafael
A1  - Ritz, Thomas
A1  - Wallenborn, Ramona
T1  - Unterschiedliche Entwicklungsansätze von Multiplattform-Anwendungen : Marktübersicht
N2  - Die Marktübersicht „Unterschiedliche Entwicklungsansätze von Multiplattform-Anwendungen“ richtet sich an IT-Dienstleister, Entwickler und IT-Abteilungen von Unternehmen, die Multiplattform Anwendungen entwickeln. In dieser Marktübersicht werden verschiedene Entwicklungsansätze beschrieben und ihre jeweiligen Vor- und Nachteile aufgezeigt.
Y1  - 2014
N1  - Mittelstand Digital
PB  - eBusiness-Lotse
CY  - Aachen
ER  - 
TY  - BOOK
A1  - Galley, Birgit
A1  - Minoggio, Ingo
A1  - Schuba, Marko
A1  - Bischoff, Barbara
A1  - Höfken, Hans-Wilhelm
T1  - Unternehmenseigene Ermittlungen : Recht - Kriminalistik - IT
Y1  - 2016
SN  - 978-3-503-16531-5
PB  - Erich Schmidt Verlag
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Ferrein, Alexander
A1  - Jacobs, Stefan
A1  - Lakemeyer, Gerhard
T1  - Unreal Golog Bots / Jacobs, Stefan ; Ferrein, Alexander ; Lakemeyer, Gerhard
JF  - IJCAI-05 Workshop on Reasoning, Representation, and Learning in Computer Games
Y1  - 2005
SP  - 31
EP  - 36
ER  - 
TY  - CHAP
A1  - Engels, Elmar
A1  - Gabler, Thomas
T1  - Universelle Programmierschnittstelle für Motion-Logic Systeme : Struktur, Funktionen und Anwendung in der Forschung und Lehre
N2  - Mit freundlicher Genehmigung der Autoren und des Oldenbourg Industrieverlags https://www.oldenbourg-industrieverlag.de/de/9783835633223-33223 erschienen als Beitrag im Tagungsband zur AALE-Tagung 2012. 9. Fachkonferenz 4.-5. Mai 2012, Aachen, Fachhochschule. ISBN 9783835633223 S 2-1 S. 37-46 Original-Abstract der Autoren: "Dieser Artikel beschreibt eine universelle Programmierschnittstelle zur Entwicklung von Motion-Logic Applikationen für industrielle Motion-Controller. Sie ermöglicht die Entwicklung von Software mit modernen Hochsprachen, wie C/C++. Visual Basic, C#, Java, Objective-Cund visuellen Programmiersprachen, wie LabVIEW in Koexistenz mit klassischen Programmiersprachen für speicherprogrammierbare Steuerungen nach IEC 61131-3. Daraus ergeben sich neue Möglichkeiten industrielle Antriebs- und Steuerungssysteme mit ihrem IT-Umfeld zu verbinden."
KW  - Speicherprogrammierte Steuerung
KW  - Motion-Logic System
KW  - SPS
KW  - IndraMotion
Y1  - 2012
ER  - 
TY  - CHAP
A1  - Engels, Elmar
A1  - Gabler, T.
T1  - Universelle Programmierschnittstelle für Motion-Logic Systeme
T2  - Tagungsband zur AALE-Tagung 2012 : 9. Fachkonferenz
Y1  - 2012
SN  - 978-3-8356-3305-6
N1  - AALE 2012
SP  - 37
EP  - 46
PB  - Oldenbourg Industrieverlag
CY  - München
ER  -